Temporal Dynamics of the Milk Proteome in Women with Gestational Diabetes Mellitus

Objectives: To characterize the temporal dynamics of the breast milk proteome between women with gestational diabetes mellitus (GDM) and healthy controls across various lactation periods and to explore the potential impacts of these proteomic differences on offspring growth. Methods: Twenty mothers with GDM and 20 healthy mothers were included. Human milk samples were obtained at four distinct time points: colostrum, transitional milk, early mature milk, and mature milk. Shotgun proteomics with label-free quantification was applied to analyze the milk proteome. Differentially expressed proteins were determined, and their functional roles were explored by GO enrichment and KEGG analyses. A random forest model was used to identify proteins distinguishing GDM milk. Correlations between differentially expressed proteins and infant anthropometric indices were also assessed. Results: Principal coordinate analysis (PCoA) revealed distinct separations in the milk proteome of GDM and healthy mothers, diminishing over time. The upregulated proteins in GDM were linked to the innate immune system, complement and coagulation cascades, cellular secretion, enzymatic and binding activity, and platelet activation. Six proteins effectively distinguished groups (AUC = 0.91). Twenty-eight proteins exhibited consistent changes across stages, correlating with offspring anthropometry. Conclusions: GDM significantly influences the milk proteome, with the extent of alteration diminishing as lactation progresses.